When did Borussia Dortmund last lose at home in the Champions League?

Jack Beresford:

Borussia Dortmund last lost a Champions League game at the Westfalenstadion back in the 2011/12 edition of the Champions League.

Dortmund were defeated 3-2 by Olympique Marseille on December 6th 2012 after surrendering  a 2-0 lead against the French side.